I have now been an iPhone owner for two years. The phone is sold as operator locked here in Finland, but once the one or two year contract is up, the operator will unlock your phone if you ask. I called Sonera's customer support, explained what I wanted and the customer representative at the other end told me to wait 5 minutes and then sync the phone with iTunes using a non-Sonera SIM card. I did this and iTunes told med "Congratulations, your iPhone has been unlocked."
The choice of word - congratulations - is kind of ironic. But now I have an officially unlocked iPhone 3G.